A classical problem facing many software projects is determining when to stop testing and release the product for use. Risk analysis helps address this issue by balancing the risk exposure of doing too little with the risk exposure of doing too much. A quantitative approach based on the COCOMO II cost-estimation model and the COQUALMO quality-estimation model helps answer the question, "How much software quality investment is enough?" The authors use the models and some representative empirical data to assess the relative payoff of value-based testing as compared to value-neutral testing. They include examples of the approach's use under differing value profiles.